Insulating walk-up attic door?


#1

In my quest to keep warm air from getting up to my cold attic, I was thinking about my walk-up attic door.

It has weather stripping around the sides/top and a big piece of foam at the bottom, both to cut down draft.

But the door itself is just a 1920’s solid wood door. I was thinking of how I could make it more insulated.

Attach some rigid foam insulation like Owens Foamular 2" to the inside of the door?

Cover the stair opening in the attic floor with something similar?

Any good ideas/tricks?


#2

I think yall know my answer. :slight_smile:


#3

Sorry I haven’t been on this board long enough to know what you’d say. So wanna lay it on me? As long as it’s cheap! :wink:


#4

FIRE UP THE RIG AND SPRAY THAT SUCKER.


#5

Still not quite sure what you’re suggesting. But something tells me I don’t like it.


#6

is that polyura there Aaron???


#7

Here’s what I’ve found:

2" foam is R10
1" foam is R5
2" foam w/ aluminum facing 2-sides (“thermal sheeting”) is R14.4
1" of the same thermal sheeting is R7.2

I’m thinking of using 1" thermal sheeting (aluminum faced) R7.2 on the back of the door, plus 2" regular foam (unfaced) R10 over the stair hole.

Remember I have a standard solid door at the bottom, then a fixed flight of stairs that go up to the attic floor.

I like the 1" aluminum on the door b/c it’s thinner. But I have to look at a piece to see if aluminum is durable enough to hold up.

I like the 2" unfaced over the hole b/c it’s pretty heavy, and thick enough to (hopefully) not sag over the hole. One reason I’m thinking of not using the aluminum here is that this piece will be slid over the floor a lot and I imagine the aluminum tearing.

The last thing I’m wondering is if there’s any problem creating these stagnant air pockets: (1) big triangular pocket in stairs between door & floor, and 6 very small pockets on the back of door b/c of recessed panels.

I’m not inviting mold & mildew am I? And this is a reasonably effective way of insulating?

As you know, I haven’t been to school in this stuff. :mrgreen:


#8

Now that i understand the question Rich maybe using some weatherstrip would help you out to. As far as gaps in the insulation i would make sure there are none. Like we talked about on the phone that insulation is a very important part from keeping the heated moist air from comming in the attic.

I chatted with my siding installer and he said putting a screen over the cont. soffit is easy to do since they are cutting out the soffit and installing new wood.


#9

The attic door is already weather-stripped. I’m not worried about drafts so much as heat transfer.

Right now, the attic floor is insulated, except for the 3’ x 8’ hole where the staircase is. Seemed like something I should address.

I guess it wasn’t clear from my description about which pockets of air I was talking about.

The main one is the “big triangle” in the stair case area. Looking in cross-section, imagine a triangle with the door as one side, the stairs as anonther and the hole in the floor (the plane of the attic floor) as the 3rd.

If I cover the hole with a sheet of foam insulation as I’m thinking, then by definition I trap that big triangle of air.

My gut feeling is the pockets of air are OK. My only significant concern is with trapping stagnant air in the big triangle area and if that could inspire mold/mildew. I guess I could just monitor it.

-Rich


#10

Thanks a lot for inquiring for me. I came to the same conclusion myself when I talked with a carpenter more about how the vent would be secured.

The only thing stopping me from doing it is the loss in air flow. The whole reason for doing continuous vs. round mini-louvers is to maximize air flow to solve my moisture/condensation/mold problem.

I’ll probably try to find someone knowledgable at AirVent to talk to about the air flow issue. If anyone has a lead there or anywhere else just PM me the info.

-Rich


#11

Update…

For 2 weeks I’ve been using the 2" foam board w/ foil both sides (R13) to cover the hole where my staircase penetrates attic floor. And it seems to work great.

You can tell immediately upon opening the door at the bottom of the attic stairs. It used to be a rush of cold air. No more!

And sliding it off & on is easy. I duct taped the edges, otherwise they would’ve gotten torn up pretty quickly.

Also I didn’t bother to do anything to the inside of the attic door… doesn’t seem necessary now that the hole above covered/insulated.